Conventionally, there has been known a substrate processing system that performs a substrate process, such as a liquid process with a processing liquid or a gas process with a processing gas, to a substrate such as a semiconductor wafer, or the like.
By way of example, a substrate processing system described in Patent Document 1 includes multiple substrate processing units stacked in multiple stages, a substrate accommodating unit capable of accommodating multiple substrates loaded from the outside, two substrate transfer apparatuses stacked up and down to respectively correspond to an upper group and a lower group of the multiple substrate processing units and configured to unload substrates from the substrate accommodating unit and load the substrates into the substrate processing units, and a substrate delivery apparatus configured to deliver a substrate accommodated in the substrate accommodating unit to another position in the substrate accommodating unit.
In this substrate processing system, the substrates loaded from the outside are accommodated at an accommodation position in a lower portion within the substrate accommodating unit. Then, substrates, which are processed in the lower group of the substrate processing units, are unloaded by the substrate transfer apparatus corresponding to the lower group, and then, loaded into the lower group of the substrate processing units. Further, substrates, which are processed in the upper group of the substrate processing units, are delivered by the substrate delivery apparatus to an accommodation position in an upper portion within the substrate accommodating unit. Subsequently, the substrates are unloaded by the substrate transfer apparatus corresponding to the upper group, and then loaded into the upper group of the substrate processing units.
Patent Document 1: Japanese Patent Publication No. 5000627
However, in the substrate processing system described in Patent Document 1, a single substrate delivery apparatus unloads or transfers substrates between a lower accommodation position and an upper accommodation position, so that a moving distance of the substrate displacing apparatus is increased. For this reason, it is difficult to increase the number of wafers to be transferred per unit time in the substrate processing system.